JPH0126161Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a posture control device for maintaining the horizontal posture of a ground work device such as a rotary tiller that is towed by a tractor to perform field cultivation work.
It is related to

When a ground work device such as a rotary cultivator, which is connected to this machine such as a tractor and is raised and lowered by a hydraulic lift cylinder, is used for ground work such as plowing in a lower working position that acts on the field, the ground work device is connected to this machine. When tilting to follow the slope of the machine, it is not possible to obtain consistent work results such as a constant plowing depth. Therefore, a posture control device such as the one described above is installed, so that even if the machine is tilted, the ground work equipment will not work. has already been maintained in a horizontal position.

This type of attitude control device is equipped with a double-acting hydraulic cylinder that changes the attitude of the ground work equipment, and operates the hydraulic cylinder using a solenoid valve whose position is switched and controlled by a sensor that detects the attitude of the ground work equipment. The system is configured to control the supply of oil to maintain the ground work equipment in a horizontal position.

By the way, since the dead weight of the ground work device is always applied to the above-mentioned hydraulic cylinder in the direction of lowering the work device, when the posture is corrected by raising or lowering one end of the ground work device using the hydraulic cylinder, The raising and lowering speeds of the work equipment are significantly different. This is a major disadvantage in achieving the purpose of a posture control device installed for the purpose of horizontally cultivating the topsoil of a field. Further, if there is a sudden change in unevenness in the concave surface and the ground working device is rapidly displaced in the downward direction, which is the direction in which its own weight is applied, an impact force is applied to various parts of the working device, which may cause damage.

Next, the optimum speed of the above-mentioned hydraulic cylinder varies depending on the type of ground work equipment and the running speed of the machine.

In other words, when doing plowing work using a plowing machine, for example, the resistance received from the field side is small and the running speed of the machine is high, so the speed of the hydraulic cylinder should be increased to quickly correct the posture of the work machine. On the other hand, in work using a working machine such as a trencher that penetrates deep into the soil, if the speed of the hydraulic cylinder is high, the working machine will be strongly pressed against the sides of the excavation trench, causing bending or damage.

If the cylinder speed is too low during work with high traveling speeds, the sensor will detect a convex part of the field and when the hydraulic cylinder operates to bring the work equipment into a horizontal position, the machine will have already passed the convex part of the field. Problems that have already been solved arise. On the other hand, if the cylinder speed is too high during work at low travel speeds, the attitude of the work equipment may be corrected too quickly, resulting in uneven fields instead of being finished smoothly, or the attitude of the work equipment may be corrected excessively beyond the horizontal position. Problems such as being lost may occur.

The purpose of this invention is to provide a new attitude control device for ground work equipment that solves the above-mentioned problems.

Regarding the illustrated embodiment, the structure of this invention will be explained. In Fig. 1, 1 is an agricultural tractor, and a rotary tiller 2, which is an example of a ground work device, is connected to the rear of the tractor 1 to be pulled. There is. As usual, this connection is made using one upper link 3 and two left and right lower links 4, and the left and right lift arms 6 of a hydraulic lift device 5 installed at the top of the rear of the tractor 1 are connected. It is connected to the left and right lower links 4 by left and right tie rods 7, and the rotary tiller 2 can be raised and lowered by a hydraulic lift cylinder 8 (FIG. 2) of a hydraulic lift device 5. A double-acting hydraulic cylinder 9 is inserted into the tie rod 7 on one side and changes the attitude of the rotary tiller 2 by expanding and contracting the tie rod 7. Further, a sensor 10 such as a mercury switch is provided on the rotary tiller 2 to detect the attitude of the tiller 2. In Fig. 1, 11 extends rearward from the tractor 1.
The PTO shaft 12 is a flexible transmission shaft mechanism that transmits driving force from the PTO shaft 11 to the rotary tiller 2.

A hydraulic circuit as shown in FIG. 2 is provided in order to correct the attitude of the rotary tiller 2 by extending and contracting the hydraulic cylinder 9 when the rotary tiller 2 is tilted from side to side. As shown in the figure, oil tank 1
3 supplies hydraulic oil to the primary side of the control valve device 15 for the hydraulic lift cylinder 8 by means of a hydraulic pump 14.A hydraulic oil supply circuit 16 for the hydraulic lift cylinder 8 is branched from the hydraulic pump 14 to supply hydraulic oil to the primary side of the control valve device 15 for the hydraulic lift cylinder 8. A refueling circuit 17 is provided,
Hydraulic oil is supplied to the hydraulic lift cylinder 8 and the attitude control hydraulic cylinder 9 by a single hydraulic pump 14. A variable throttle 18 inserted into the oil supply circuit 17 and the oil pressure of the oil supply circuit 17 on the secondary side of the variable throttle 18 inserted into the oil supply circuit 16 are applied as back pressure to the branch parts of both the oil supply circuits 16 and 17 described above. A flow rate regulating valve 20 is provided in combination with a certain relief valve 19.

The hydraulic cylinder 9 moves one end of the rotary tiller 2 up during a contraction operation and lowers during an extension operation.
Although the attitude of the cultivator 2 is controlled, in order to selectively operate the hydraulic cylinder 9, as shown in FIG. A solenoid valve 21 is provided which is connected to. This solenoid valve 21
The primary side tank port 21T is connected to the oil tank 13 by an oil drain circuit 22, and the solenoid valve 2
Two cylinder ports 21C _a , 2 on the secondary side of 1
_1Cb is connected to the expansion oil chamber 9a and the contraction oil chamber 9b of the attitude control hydraulic cylinder 9 through oil supply and drainage circuits 23A and 23B, respectively. The solenoid valve 21 has three positions, and at the neutral position N shown in the figure, both cylinder ports 21C _a , 2
1C _b is blocked to stop the hydraulic cylinder 9, and the pump port 21P and tank port 21 are
The pump port 21P is connected to the pump port 21P at the operating position A, which is moved by the excitation of the solenoid 21A.
and the cylinder port 21C _a are communicated, and the cylinder port 21C _b and the tank port 21T are communicated to extend the hydraulic cylinder 9, and conversely, the pump port is moved to another working position B by the excitation of the other solenoid 21B. 21P and the cylinder port 21C _b are communicated with each other, and the cylinder port 21C _a and the tank port 21T are communicated with each other to cause the attitude control hydraulic cylinder 9 to perform a contracting operation. Each solenoid 2 mentioned above
1A and 21B are selectively energized as usual when the sensor 10 detects the inclination of the rotary tiller 2 in one direction or the other.

Similarly, as shown in FIG. 2, according to this invention, the above-mentioned oil supply and drain circuit 23B, that is, when refueling through it, the rotary tiller 2 is raised in the retracting direction, and when oil is drained, the rotary tiller 2 is lowered. The hydraulic cylinders 9 are inserted into the oil supply/drainage circuits 23B on the side where they are respectively operated, and the check valves 24 and the variable throttles 25, which allow oil to flow only in the direction of the hydraulic cylinders 9, are connected to each other in the extension direction. They are connected in parallel. Therefore, when the rotary tiller 2 is raised and the hydraulic cylinder 9 performs a contraction operation, hydraulic oil is supplied to the contraction oil chamber 9b via the check valve 24, whereas when the rotary tiller 2 is lowered, the hydraulic oil is supplied to the contraction oil chamber 9b. That is, when the hydraulic cylinder 9 is extended to displace the cultivator 2 in the downward direction under its own weight, the hydraulic oil is slowly discharged from the reduction oil chamber 9b through the variable throttle 25, thereby causing the hydraulic cylinder 9 to extend. Therefore, the rotary power tiller 2 is not lowered suddenly.

The above-mentioned oil supply/discharge circuit 23B also has another reverse circuit, which is closer to the electromagnetic valve 21 than the above-mentioned check valve 24 and variable throttle 25, and which, like the above-mentioned check valve 24, allows oil flow only in the direction of the hydraulic cylinder 9. A stop valve 26 is inserted and installed. The other check valve 26 is such that when the solenoid valve 21 is in the neutral position N, the hydraulic cylinder 9 unexpectedly expands due to the weight of the rotary tiller 2, accompanied by an oil drain from the reduction oil chamber 9b. This is to prevent the device from operating.
The solenoid valve 21 is moved to the operating position A and the hydraulic cylinder 9
When the is extended, the oil supply/discharge circuit 23
It is constructed so that it is opened by the action of the oil pressure established at A and allows oil to be drained from the reduction oil chamber 9b.

Similarly, as shown in FIG. 2, the variable diaphragm 25 is configured as a valve that can be displaced to a plurality of positions a, a, a, according to this invention.
The aperture degree is assumed to decrease in the order of a and a. The variable throttle 18 inserted into the oil supply circuit 17 is also constructed as a valve that can be displaced to a plurality of positions b, b, b.
The aperture degree is assumed to decrease in the order of b. These two apertures 25 and 18 are interlocked with each other to achieve positions a, b, positions a, b, and positions a,
suitable interlocking means 1 so as to be transferred to b.
They are interlocked and connected to each other by 00.

Specifically, the portion described above is configured as shown in FIG. 3, for example. That is, the part shown surrounded by the two-dot chain line in FIG. 2 is unified as an attitude control valve device 33 as will be described later, but as shown in FIG.
The valve case 101 of No. 3 includes oil passages 102, 103, 104 that constitute a part of the oil supply circuit 17, and an oil passage 105 that constitutes a part of the oil supply and discharge circuit 23B.
106 and 107 are arranged and drilled as shown in the figure. A pair of tapered portions 10 facing into the oil passages 103 and 104 are arranged concentrically with each other.
An adjusting screw 110 having a diameter of 8,109 is screwed into the valve case 101, and the oil passage 10
While the oil flows in the direction of the solenoid valve 21 in the order of 2, 103, 104, the oil passage 103 is constricted by the tapered part 108 to form the throttle 18,
While oil flows in the order of oil passages 105, 106, and 107 toward the reduction oil chamber 9b of the hydraulic cylinder 9, the oil passage 106 is constricted by the tapered portion 109 to form the throttle 25. Adjustment screw 110
A handle 111 is attached outside the valve case 101. As described above, the apertures 25 and 18 shown in FIG. 3 are operated in conjunction with each other to increase or decrease the aperture degree by rotating the adjusting screw 110 by operating the handle 111 and moving it forward or backward. .

In addition, in the illustrated case, as shown in FIG.
Insert the regulator valve 27 into
However, it is provided. That is, the regulator valve 27 is connected to the oil supply circuit 17 by the internal throttle 28.
A first position where the amount of oil supplied in the direction of the hydraulic cylinder 9 is reduced by restricting the throttle 28, and a second position where the amount of oil supplied is increased without throttling the oil supply circuit 17 by the throttle 28. It is configured with the following.

The regulator valve 27 is moved between the first position and the second position.
In order to selectively displace between the positions of
The following means are provided: That is, first, as shown in FIG. 2, the regulator valve 27 is biased toward a first position by a spring 29, and is normally in the first position. The spring 29 operating end of the valve 27 is connected to the oil drain circuit 22 through a drain circuit 30, and the other end is connected to the oil supply circuit 1 on the secondary side of the valve 27 through a pilot hydraulic action circuit 31.
7, and when oil pressure is established in the oil supply circuit 17, the oil pressure causes the spring 29 to be displaced to the second position against the force of the spring 29. Therefore, when the solenoid valve 21 is in the neutral position N, the oil supply circuit 17 is connected to the oil drain circuit 22, and no oil pressure is established in the oil supply circuit 17,
The regulator valve 27 assumes the first position under the action of the spring 29, and conversely, the solenoid valve 21 is moved to either operating position A or B, and the oil supply circuit 17 is transferred to the oil supply/discharge circuit 23A or 23B. When connected and hydraulic pressure is established in the oil supply circuit 17 to operate the hydraulic cylinder 9, the regulator valve 24 is displaced to the second position by hydraulic action.

In FIG. 2, numeral 32 is a pressure regulating valve for setting the oil pressure, and in the case shown, the above-mentioned variable throttle 1
8, flow rate adjustment valve 20, solenoid valve 21, check valve 24,
The variable throttle 25, the other check valve 26, and the regulator valve 27, including the oil passage therebetween, are combined into a unit as the above-mentioned attitude control valve device 33, as shown surrounded by a two-dot chain line in FIG. ing.

The illustrated attitude control device according to this invention is constructed as described above, so that when the sensor 10 detects a left/right inclination of the rotary tiller 2, the device moves in the direction of the inclination. Accordingly, the solenoid valve 21 is moved to either the operating position A or B, and the regulator valve 27 is then moved as described above.
is automatically displaced to the second position,
The variable throttle 1 in the oil supply circuit 17 is moved from the oil supply circuit 17 toward either the oil supply/discharge circuit 23A or 23B.
Hydraulic oil will be supplied at a rate determined by the degree of restriction of 8. If the variable throttle 25 is not provided in the oil supply/discharge circuit 23B, the solenoid valve 21 is moved to the operating position B, the hydraulic cylinder 9 is compressed, and the rotary tiller 2 is raised. Compared to the raising speed, the lowering speed of the rotary tiller 2 when the solenoid valve 21 is moved to the operating position A and the hydraulic cylinder 9 is extended to lower the rotary tiller 2 is higher than the lowering speed of the rotary tiller 2 which is applied in the same lowering direction. While it gradually increases due to the own weight of cultivator 2,
The electromagnetic valve 21 is provided with the variable throttle 25 described above.
Reduction oil chamber 9b when moved to the working position A
Since the rate of oil discharged from the rotary tiller 2 is reduced by the variable throttle 25 and the extension speed of the hydraulic cylinder 9 is lowered, the raising speed and lowering speed of the rotary tiller 2 are balanced. Therefore, the posture correction of the rotary tiller 2 is performed in a balanced manner to the left and right, and a situation where the plowing depth is made constant in the left and right directions is not biased toward one direction in the same direction. In addition, even when there is a sudden change in unevenness in the field, the rotary tiller 2 can be prevented from being lowered rapidly by restricting oil discharge from the reduction oil chamber 9b by the variable throttle 25, and the rotary tiller 2 can be prevented from being lowered rapidly. protected. The ratio of oil discharged from the reduction oil chamber 9b can be optimally adjusted by changing and adjusting the degree of restriction of the variable restrictor 25.

The speed of raising and lowering the rotary tiller 2 can be easily set using the handle 111 shown in FIG. That is, the raising speed of the rotary tiller 2 is determined by the degree of restriction of the throttle 18 in the oil supply circuit 17, and the lowering speed is determined by the degree of restriction of the throttle 18 in the oil supply circuit 17.
It is determined by the aperture degree of the aperture 25 in B, but since the aperture degrees of the two apertures 18 and 25 can be controlled to increase or decrease in conjunction with each other, the raising speed of the tiller 2 and This is because it is possible to simultaneously increase or decrease the lowering speed and set both speeds to a certain desired value at the same time.

In the case shown, the regulator valve 2
7 is provided, and when the solenoid valve 21 is in the neutral position N and the attitude of the rotary tiller 2 is not corrected by the hydraulic cylinder 9 as described above, the valve 27 is closed to the oil supply circuit by the internal throttle 28. 17
Therefore, in the above state, the amount of oil flowing through the oil supply circuit 17 is gradually lowered than the amount of oil determined by the degree of restriction of the variable throttle 18 in the circuit 17. Therefore, even when the degree of aperture of the variable orifice 18 is relatively small, the solenoid valve 2
Hydraulic lift cylinder 8 as long as 1 is in neutral position N
When a sufficient amount of oil is secured in the oil supply circuit 16 in the direction, for example, when turning the tractor 1 on a headland in a field, the control valve device 15 is operated to extend the hydraulic lift cylinder 8 to operate the rotary tiller. 2, a rapid extension movement of the hydraulic lift cylinder 8 and thus a rapid lifting of the rotary tiller 2 is obtained.

As is clear from the description of the above embodiments, the attitude control device for ground work equipment of this invention uses a double-acting hydraulic cylinder 9 for changing the attitude of ground work equipment 2.
and a solenoid valve 21 whose position is switched and controlled by a sensor 10 that detects the attitude of the ground work device 2.
A posture control device configured to maintain the ground work device 2 in a horizontal posture by controlling the supply of hydraulic oil to the hydraulic cylinder 9 by connecting the above-described solenoid valve 21 and the hydraulic cylinder 9. Of the pair of oil supply and discharge circuits 23A and 23B, the oil supply and discharge circuit on the side through which the hydraulic cylinder 9 is operated in the direction of raising the working device when refueling through it, and in the direction of lowering the working device when draining oil. 23B, a check valve 24 that allows oil to flow only in the direction of the hydraulic cylinder 9 and a throttle 25 with a variable degree of restriction are connected in parallel to each other, and an oil supply circuit 17 on the primary side of the solenoid valve 21 is provided. Other aperture with variable aperture level 1
8 is inserted and installed, and the aperture 25 and the other aperture 18
It has a configuration in which operating means 110 and 111 are provided to enable the aperture degree to be increased or decreased in conjunction with each other,
It has the following advantages:

That is, since the attitude control device of this invention is configured as described above, the ground work device 2
When raising the hydraulic cylinder 9, the hydraulic oil is supplied at a high rate through the check valve 24 described above.
is operated in the direction of raising the work equipment, whereas when lowering the ground work equipment 2, oil is drained at a low rate from the hydraulic cylinder 9 through the above-mentioned throttle 25, and the hydraulic cylinder 9 is moved in the direction of lowering the work equipment. As a result, the operating speed of the hydraulic cylinder 9 in the lowering direction of the ground work equipment 2, which is subject to the weight of the ground work equipment 2, is reduced by the throttle 25. The influence of the own weight of the working device 2 is eliminated, and the raising speed and lowering speed are balanced, and the results of ground work such as constant plowing depth in the left and right directions can be stabilized in one direction in the same left and right direction. We will make sure that situations where this is done in a biased manner do not occur. Furthermore, since the lowering speed of the ground working device 2 is moderated by the throttle 25 as described above, the posture control device of this invention prevents the ground working device 2 from descending rapidly even if there is a sudden change in unevenness in the field. As a result, impact force is prevented from being applied to each part of the work equipment 2, and the ground work equipment is protected.

In addition, the attitude control device of this invention is the ground work device 2.
The throttle 18 determines the speed of the cylinder 9 in the upward direction.
and the throttle 25 that determines the cylinder 9 speed in the downward direction.
and are respectively provided with variable aperture degrees, and both apertures 1
The hydraulic cylinder 9 simultaneously controls the aperture degrees of 8 and 25.
Since the expansion and contraction speed of the work equipment 2, that is, the raising speed and lowering speed of the work equipment 2, can be changed and controlled at the same time, the speed of the hydraulic cylinder 9 can be changed depending on the type of ground work equipment and the running speed of the machine, as mentioned at the beginning. Various problems will occur if the optimum speed is not selected using the above-mentioned method. However, the optimum cylinder speed can be easily and quickly set by simultaneously changing and controlling the speeds of nine cylinders in the lifting and lowering directions of the working device.

[Brief explanation of drawings]

Fig. 1 is a side view showing the rear part of a tractor and a rotary tiller equipped with an embodiment of this invention, Fig. 2 is a hydraulic circuit diagram of the embodiment, and Fig. 3 is a specific structural example of the main parts of the embodiment. FIG. 1...Tractor, 2...Rotary tiller, 7...
...Tie rod, 9...Hydraulic cylinder, 9a...Extension oil chamber, 9b...Reduction oil chamber, 10...Sensor, 17...Oil supply circuit, 18...Variable throttle,
21... Solenoid valve, 23A, 23B... Oil supply/discharge circuit, 24... Check valve, 25... Variable throttle, 101
...Valve case, 102, 103, 104...
Oil passage, 105, 106, 107...Oil passage, 1
08,109...Tapered portion, 110...Adjustment screw, 111...Handle.

Claims (1)

[Scope of utility model registration request] A double-acting hydraulic cylinder that changes the attitude of the ground work equipment is provided, and the supply of hydraulic oil to the hydraulic cylinder is controlled by a solenoid valve whose position is switched and controlled by a sensor that detects the attitude of the ground work equipment,
A posture control device configured to maintain ground work equipment in a horizontal position, which raises the work equipment when refueling through a pair of oil supply/drainage circuits that connect the above-mentioned solenoid valve and hydraulic cylinder. A check valve and a variable restrictor are inserted into the oil supply and drain circuits on the side where the hydraulic cylinders are operated, and allow oil to flow only in the direction of the hydraulic cylinders, and in the direction of lowering the working equipment when draining oil. and the other throttles are connected in parallel with each other, and another throttle whose degree of restriction is variable is inserted and installed in the oil supply circuit on the primary side of the solenoid valve, and the throttle and the other throttle are interlocked with each other. An attitude control device for ground-based work equipment, characterized in that it is provided with an operating means that can increase or decrease the degree of rotation.